Importance of the lactate anion in control of breathing.
The purpose of this study was to examine the effects of raising the arterial La- and K+ levels on minute ventilation (VE) in rats. Either La- or KCl solutions were infused in anesthetized spontaneously breathing Wistar rats to raise the respective ion arterial concentration ([La-] and [K+]) gradually to levels similar to those observed during strenuous exercise. VE, blood pressure, and heart rate were recorded continuously, and arterial [La-], [K+], pH, and blood gases were repeatedly measured from blood samples. To prevent changes in pH during the La- infusions, a solution of sodium lactate and lactic acid was used. Raising [La-] to 13.2 +/- 0.6 (SE) mM induced a 47.0 +/- 4.0% increase in VE without any concomitant changes in either pH or PCO2. Raising [K+] to 7.8 +/- 0.11 mM resulted in a 20.3 +/- 5.28% increase in VE without changes in pH. Thus our results show that La- itself, apart from lactic acidosis, may be important in increasing VE during strenuous exercise, and we confirm earlier results regarding the role of arterial [K+] in the control of VE during exercise.
Hardarson
T
T
Department of Physiology, University of Iceland, Reykjavik, Iceland. thorasve@rhi.hi.is
Skarphedinsson
J O
JO
Sveinsson
T
T
D000818:Animals; D007262:Infusions, Intravenous; D019344:Lactic Acid / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D008297:Male; D011188:Potassium / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D012123:Pulmonary Ventilation / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012119:Respiration / Q000187:drug effects / Q000502:physiology*
D019344:Lactic Acid; D011188:Potassium